Barbeque grills, whether fueled by gas, propane or charcoal, all contain the same basic elements: a flame, a heat retaining/radiating substance and a cooking surface or rack. Barbeque grills fueled by charcoal conventionally utilize a lighter fluid or the like to provide an initial flame. Once ignited, the heat retaining/radiating substance is the glowing charcoal which slowly burns, dissipating heat to the food suspended over the coals on the cooking rack. The disadvantage of the charcoal grill is that burning charcoal, by nature, generates combustion by-products in the form of unoxidized carbon particulate. Of course, charcoal brickettes are recognized as messy even before burning due to the charcoal dust. Yet another disadvantage of using a conventional charcoal fueled grill is that charcoal requires prolonged exposure to the flame before the coals become hot enough to burn independently of the flame and are able to sustain sufficient heat to cook the food. Yet another problem with charcoal fueled grills is flame flare-up where fatty substances and the like fall from the cooking food onto the hot charcoal brickettes, are ignited and scorch the food. These flare-ups are also hazardous to the safety of the cook.
Gas grills were devised to eliminate the disadvantages of the charcoal grill; namely--charcoal dust, the unoxidized particulate matter generated by burning charcoal and the time delay involved in heating the coals. In the conventional gas grill, a gas flame heats lava rocks suspended between the flame and the cooking rack. The lava rocks are made from a heat retaining material and provide a stable heat source for cooking food placed upon the rack. Of course, a gas grill provided with lava rocks suffered from flame flare-up when food particles or substances fell onto the rocks and ignited. In response to this problem, an intermediate rack made of a conventional masonry material was provided in place of the lava rocks. However, such gas grills failed to eliminate the problem of flame flare-up because fatty substances and the like continued to drip down from the food onto the rack (as opposed to the lava rocks) became heated, ignite, and cause a flare-up or burst of flame that scorched the food, making it undesirable for human consumption.
A further disadvantage of conventional gas grills (as well as charcoal fueled grills) is that the lava rocks (or the charcoal) gradually lose their ability to retain heat and must be replaced periodically.
Yet another disadvantage shared by both the charcoal fueled grill and the conventional gas grill is that certain areas of the cooking surface become "hotter" than other areas. This results in unevenly cooked food wherein certain portions of the food are undercooked while other portions are overcooked. Those skilled in the art will appreciate that this phenomenon is measured by the "toast test", whereby a piece of bread is set on the cooking surface and the distribution of heat is measured by a review of the toasted and non-toasted portions of the bread. Manufacturers of gas grills have long realized and wrestled with the problem of providing an evenly distributed heat transfer for the heat source to the cooking surface.
In short, there exists a need for a grill that eliminates flame flare-up and provides an even distribution of heat.